X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Ftimesync%2Ftimesyncd.c;h=732f5bf6c2843e4724063e819fc6afd76fe62f2f;hp=f2206cc2ac515bcedf7067fd3ed93f7641a0467b;hb=0014a4ad505d119c7ac4346d9d774c3f17f663a5;hpb=16c058ba014e210fd8f6833a56787815c1059e1f

diff --git a/src/timesync/timesyncd.c b/src/timesync/timesyncd.c
index f2206cc2a..732f5bf6c 100644
--- a/src/timesync/timesyncd.c
+++ b/src/timesync/timesyncd.c
@@ -3,7 +3,7 @@
 /***
   This file is part of systemd.
 
-  Copyright 2014 Kay Sievers
+  Copyright 2014 Kay Sievers, Lennart Poettering
 
   systemd is free software; you can redistribute it and/or modify it
   under the terms of the GNU Lesser General Public License as published by
@@ -33,6 +33,9 @@
 #include <sys/timex.h>
 #include <sys/socket.h>
 #include <resolv.h>
+#include <sys/prctl.h>
+#include <sys/types.h>
+#include <grp.h>
 
 #include "missing.h"
 #include "util.h"
@@ -42,9 +45,17 @@
 #include "list.h"
 #include "ratelimit.h"
 #include "strv.h"
+#include "conf-parser.h"
 #include "sd-event.h"
 #include "sd-resolve.h"
 #include "sd-daemon.h"
+#include "sd-network.h"
+#include "event-util.h"
+#include "network-util.h"
+#include "clock-util.h"
+#include "capability.h"
+#include "mkdir.h"
+#include "timesyncd.h"
 
 #define TIME_T_MAX (time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1)
 
@@ -116,73 +127,6 @@ struct ntp_msg {
         struct ntp_ts trans_time;
 } _packed_;
 
-typedef struct Manager Manager;
-typedef struct ServerAddress ServerAddress;
-typedef struct ServerName ServerName;
-
-struct ServerAddress {
-        union sockaddr_union sockaddr;
-        socklen_t socklen;
-        LIST_FIELDS(ServerAddress, addresses);
-};
-
-struct ServerName {
-        char *string;
-        LIST_HEAD(ServerAddress, addresses);
-        LIST_FIELDS(ServerName, names);
-};
-
-struct Manager {
-        sd_event *event;
-        sd_resolve *resolve;
-
-        LIST_HEAD(ServerName, servers);
-
-        RateLimit ratelimit;
-
-        /* peer */
-        sd_resolve_query *resolve_query;
-        sd_event_source *event_receive;
-        ServerName *current_server_name;
-        ServerAddress *current_server_address;
-        int server_socket;
-        uint64_t packet_count;
-        sd_event_source *event_timeout;
-
-        /* last sent packet */
-        struct timespec trans_time_mon;
-        struct timespec trans_time;
-        usec_t retry_interval;
-        bool pending;
-
-        /* poll timer */
-        sd_event_source *event_timer;
-        usec_t poll_interval_usec;
-        bool poll_resync;
-
-        /* history data */
-        struct {
-                double offset;
-                double delay;
-        } samples[8];
-        unsigned int samples_idx;
-        double samples_jitter;
-
-        /* last change */
-        bool jumped;
-        int drift_ppm;
-
-        /* watch for time changes */
-        sd_event_source *event_clock_watch;
-        int clock_watch_fd;
-
-        /* Retry connections */
-        sd_event_source *event_retry;
-
-        /* Handle SIGINT/SIGTERM */
-        sd_event_source *sigterm, *sigint;
-};
-
 static void manager_free(Manager *m);
 DEFINE_TRIVIAL_CLEANUP_FUNC(Manager*, manager_free);
 #define _cleanup_manager_free_ _cleanup_(manager_freep)
@@ -208,6 +152,56 @@ static double square(double d) {
         return d * d;
 }
 
+static int load_clock_timestamp(uid_t uid, gid_t gid) {
+        _cleanup_close_ int fd = -1;
+        usec_t min = TIME_EPOCH * USEC_PER_SEC;
+        usec_t ct;
+        int r;
+
+        /* Let's try to make sure that the clock is always
+         * monotonically increasing, by saving the clock whenever we
+         * have a new NTP time, or when we shut down, and restoring it
+         * when we start again. This is particularly helpful on
+         * systems lacking a battery backed RTC. We also will adjust
+         * the time to at least the build time of systemd. */
+
+        fd = open("/var/lib/systemd/clock", O_RDWR|O_CLOEXEC, 0644);
+        if (fd >= 0) {
+                struct stat st;
+                usec_t stamp;
+
+                /* check if the recorded time is later than the compiled-in one */
+                r = fstat(fd, &st);
+                if (r >= 0) {
+                        stamp = timespec_load(&st.st_mtim);
+                        if (stamp > min)
+                                min = stamp;
+                }
+
+                /* Try to fix the access mode, so that we can still
+                   touch the file after dropping priviliges */
+                fchmod(fd, 0644);
+                fchown(fd, uid, gid);
+
+        } else
+                /* create stamp file with the compiled-in date */
+                touch_file("/var/lib/systemd/clock", true, min, uid, gid, 0644);
+
+        ct = now(CLOCK_REALTIME);
+        if (ct < min) {
+                struct timespec ts;
+                char date[FORMAT_TIMESTAMP_MAX];
+
+                log_info("System clock time unset or jumped backwards, restoring from recorded timestamp: %s",
+                         format_timestamp(date, sizeof(date), min));
+
+                if (clock_settime(CLOCK_REALTIME, timespec_store(&ts, min)) < 0)
+                        log_error("Failed to restore system clock: %m");
+        }
+
+        return 0;
+}
+
 static int manager_timeout(sd_event_source *source, usec_t usec, void *userdata) {
         _cleanup_free_ char *pretty = NULL;
         Manager *m = userdata;
@@ -216,7 +210,7 @@ static int manager_timeout(sd_event_source *source, usec_t usec, void *userdata)
         assert(m->current_server_name);
         assert(m->current_server_address);
 
-        sockaddr_pretty(&m->current_server_address->sockaddr.sa, m->current_server_address->socklen, true, &pretty);
+        server_address_pretty(m->current_server_address, &pretty);
         log_info("Timed out waiting for reply from %s (%s).", strna(pretty), m->current_server_name->string);
 
         return manager_connect(m);
@@ -256,7 +250,7 @@ static int manager_send_request(Manager *m) {
         ntpmsg.trans_time.sec = htobe32(m->trans_time.tv_sec + OFFSET_1900_1970);
         ntpmsg.trans_time.frac = htobe32(m->trans_time.tv_nsec);
 
-        sockaddr_pretty(&m->current_server_address->sockaddr.sa, m->current_server_address->socklen, true, &pretty);
+        server_address_pretty(m->current_server_address, &pretty);
 
         len = sendto(m->server_socket, &ntpmsg, sizeof(ntpmsg), MSG_DONTWAIT, &m->current_server_address->sockaddr.sa, m->current_server_address->socklen);
         if (len == sizeof(ntpmsg)) {
@@ -267,7 +261,7 @@ static int manager_send_request(Manager *m) {
                 return manager_connect(m);
         }
 
-        /* re-arm timer with incresing timeout, in case the packets never arrive back */
+        /* re-arm timer with increasing timeout, in case the packets never arrive back */
         if (m->retry_interval > 0) {
                 if (m->retry_interval < NTP_POLL_INTERVAL_MAX_SEC * USEC_PER_SEC)
                         m->retry_interval *= 2;
@@ -434,15 +428,17 @@ static int manager_adjust_clock(Manager *m, double offset, int leap_sec) {
         if (r < 0)
                 return r;
 
+        touch("/var/lib/systemd/clock");
+
         m->drift_ppm = tmx.freq / 65536;
 
         log_debug("  status       : %04i %s\n"
-                  "  time now     : %li.%03lli\n"
+                  "  time now     : %li.%03llu\n"
                   "  constant     : %li\n"
                   "  offset       : %+.3f sec\n"
                   "  freq offset  : %+li (%i ppm)\n",
                   tmx.status, tmx.status & STA_UNSYNC ? "" : "sync",
-                  tmx.time.tv_sec, tmx.time.tv_usec / NSEC_PER_MSEC,
+                  tmx.time.tv_sec, (unsigned long long) (tmx.time.tv_usec / NSEC_PER_MSEC),
                   tmx.constant,
                   (double)tmx.offset / NSEC_PER_SEC,
                   tmx.freq, m->drift_ppm);
@@ -548,7 +544,6 @@ static bool sockaddr_equal(union sockaddr_union *a, union sockaddr_union *b) {
 }
 
 static int manager_receive_response(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
-        _cleanup_free_ char *pretty = NULL;
         Manager *m = userdata;
         struct ntp_msg ntpmsg;
 
@@ -638,12 +633,18 @@ static int manager_receive_response(sd_event_source *source, int fd, uint32_t re
 
         m->event_timeout = sd_event_source_unref(m->event_timeout);
 
+        if (be32toh(ntpmsg.recv_time.sec) < TIME_EPOCH + OFFSET_1900_1970 ||
+            be32toh(ntpmsg.trans_time.sec) < TIME_EPOCH + OFFSET_1900_1970) {
+                log_debug("Invalid reply, returned times before epoch. Ignoring.");
+                return manager_connect(m);
+        }
+
         if (NTP_FIELD_LEAP(ntpmsg.field) == NTP_LEAP_NOTINSYNC) {
                 log_debug("Server is not synchronized. Disconnecting.");
                 return manager_connect(m);
         }
 
-        if (NTP_FIELD_VERSION(ntpmsg.field) != 4 && NTP_FIELD_VERSION(ntpmsg.field) != 3) {
+        if (!IN_SET(NTP_FIELD_VERSION(ntpmsg.field), 3, 4)) {
                 log_debug("Response NTPv%d. Disconnecting.", NTP_FIELD_VERSION(ntpmsg.field));
                 return manager_connect(m);
         }
@@ -704,7 +705,7 @@ static int manager_receive_response(sd_event_source *source, int fd, uint32_t re
                   "  delay        : %+.3f sec\n"
                   "  packet count : %"PRIu64"\n"
                   "  jitter       : %.3f%s\n"
-                  "  poll interval: %llu\n",
+                  "  poll interval: " USEC_FMT "\n",
                   NTP_FIELD_LEAP(ntpmsg.field),
                   NTP_FIELD_VERSION(ntpmsg.field),
                   NTP_FIELD_MODE(ntpmsg.field),
@@ -721,14 +722,14 @@ static int manager_receive_response(sd_event_source *source, int fd, uint32_t re
                   m->poll_interval_usec / USEC_PER_SEC);
 
         if (!spike) {
+                m->sync = true;
                 r = manager_adjust_clock(m, offset, leap_sec);
                 if (r < 0)
                         log_error("Failed to call clock_adjtime(): %m");
         }
 
-        sockaddr_pretty(&m->current_server_address->sockaddr.sa, m->current_server_address->socklen, true, &pretty);
-        log_info("%s (%s): interval/delta/delay/jitter/drift %llus/%+.3fs/%.3fs/%.3fs/%+ippm%s",
-                 strna(pretty), m->current_server_name->string, m->poll_interval_usec / USEC_PER_SEC, offset, delay, m->samples_jitter, m->drift_ppm,
+        log_info("interval/delta/delay/jitter/drift " USEC_FMT "s/%+.3fs/%.3fs/%.3fs/%+ippm%s",
+                 m->poll_interval_usec / USEC_PER_SEC, offset, delay, m->samples_jitter, m->drift_ppm,
                  spike ? " (ignored)" : "");
 
         r = manager_arm_timer(m, m->poll_interval_usec);
@@ -781,7 +782,7 @@ static int manager_begin(Manager *m) {
 
         m->poll_interval_usec = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC;
 
-        sockaddr_pretty(&m->current_server_address->sockaddr.sa, m->current_server_address->socklen, true, &pretty);
+        server_address_pretty(m->current_server_address, &pretty);
         log_info("Using NTP server %s (%s).", strna(pretty), m->current_server_name->string);
         sd_notifyf(false, "STATUS=Using Time Server %s (%s).", strna(pretty), m->current_server_name->string);
 
@@ -833,7 +834,7 @@ static int manager_resolve_handler(sd_resolve_query *q, int ret, const struct ad
         m->resolve_query = sd_resolve_query_unref(m->resolve_query);
 
         if (ret != 0) {
-                log_error("Failed to resolve %s: %s", m->current_server_name->string, gai_strerror(ret));
+                log_debug("Failed to resolve %s: %s", m->current_server_name->string, gai_strerror(ret));
 
                 /* Try next host */
                 return manager_connect(m);
@@ -974,6 +975,28 @@ static int manager_add_server(Manager *m, const char *server) {
         return 0;
 }
 
+static int manager_add_server_string(Manager *m, const char *string) {
+        char *w, *state;
+        size_t l;
+        int r;
+
+        assert(m);
+        assert(string);
+
+        FOREACH_WORD_QUOTED(w, l, string, state) {
+                char t[l+1];
+
+                memcpy(t, w, l);
+                t[l] = 0;
+
+                r = manager_add_server(m, t);
+                if (r < 0)
+                        log_error("Failed to add server %s to configuration, ignoring: %s", t, strerror(-r));
+        }
+
+        return 0;
+}
+
 static void manager_disconnect(Manager *m) {
         assert(m);
 
@@ -996,6 +1019,8 @@ static int manager_new(Manager **ret) {
         _cleanup_manager_free_ Manager *m = NULL;
         int r;
 
+        assert(ret);
+
         m = new0(Manager, 1);
         if (!m)
                 return -ENOMEM;
@@ -1008,18 +1033,16 @@ static int manager_new(Manager **ret) {
         if (r < 0)
                 return r;
 
-        sd_event_add_signal(m->event, &m->sigterm, SIGTERM, NULL,  NULL);
-        sd_event_add_signal(m->event, &m->sigint, SIGINT, NULL, NULL);
+        sd_event_set_watchdog(m->event, true);
+
+        sd_event_add_signal(m->event, NULL, SIGTERM, NULL,  NULL);
+        sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL);
 
         r = sd_resolve_default(&m->resolve);
         if (r < 0)
                 return r;
 
         r = sd_resolve_attach_event(m->resolve, m->event, 0);
-        if (r < 0)
-                return 0;
-
-        r = manager_clock_watch_setup(m);
         if (r < 0)
                 return r;
 
@@ -1036,26 +1059,157 @@ static void manager_free(Manager *m) {
         manager_disconnect(m);
         manager_flush_names(m);
 
-        sd_event_source_unref(m->sigint);
-        sd_event_source_unref(m->sigterm);
-
         sd_event_source_unref(m->event_retry);
 
+        sd_event_source_unref(m->network_event_source);
+        sd_network_monitor_unref(m->network_monitor);
+
         sd_resolve_unref(m->resolve);
         sd_event_unref(m->event);
 
         free(m);
 }
 
+int config_parse_servers(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                unsigned section_line,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        Manager *m = userdata;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+
+        manager_flush_names(m);
+        manager_add_server_string(m, rvalue);
+
+        return 0;
+}
+
+static int manager_parse_config_file(Manager *m) {
+        return config_parse(NULL, "/etc/systemd/timesyncd.conf", NULL,
+                            "Time\0",
+                            config_item_perf_lookup, timesyncd_gperf_lookup,
+                            false, false, true, m);
+}
+
+static bool network_is_online(void) {
+        _cleanup_free_ char *state = NULL;
+        int r;
+
+        r = sd_network_get_operational_state(&state);
+        if (r >= 0 && STR_IN_SET(state, "routable", "degraded"))
+                return true;
+
+        return false;
+}
+
+static int manager_network_event_handler(sd_event_source *s, int fd, uint32_t revents,
+                                         void *userdata) {
+        Manager *m = userdata;
+        bool connected, online;
+        int r;
+
+        assert(m);
+
+        /* check if the machine is online */
+        online = network_is_online();
+
+        /* check if the client is currently connected */
+        connected = (m->server_socket != -1);
+
+        if (connected && !online) {
+                log_info("No network connectivity, watching for changes.");
+                manager_disconnect(m);
+        } else if (!connected && online) {
+                log_info("Network configuration changed, trying to establish connection.");
+                if (m->current_server_address) {
+                        r = manager_begin(m);
+                        if (r < 0)
+                                return r;
+                } else {
+                        r = manager_connect(m);
+                        if (r < 0)
+                                return r;
+                }
+        }
+
+        sd_network_monitor_flush(m->network_monitor);
+
+        return 0;
+}
+
+static int manager_network_monitor_listen(Manager *m) {
+        _cleanup_event_source_unref_ sd_event_source *event_source = NULL;
+        _cleanup_network_monitor_unref_ sd_network_monitor *monitor = NULL;
+        int r, fd, events;
+
+        r = sd_network_monitor_new(&monitor, NULL);
+        if (r < 0)
+                return r;
+
+        fd = sd_network_monitor_get_fd(monitor);
+        if (fd < 0)
+                return fd;
+
+        events = sd_network_monitor_get_events(monitor);
+        if (events < 0)
+                return events;
+
+        r = sd_event_add_io(m->event, &event_source, fd, events,
+                            &manager_network_event_handler, m);
+        if (r < 0)
+                return r;
+
+        m->network_monitor = monitor;
+        m->network_event_source = event_source;
+        monitor = NULL;
+        event_source = NULL;
+
+        return 0;
+}
+
 int main(int argc, char *argv[]) {
+        const char *user = "systemd-timesync";
         _cleanup_manager_free_ Manager *m = NULL;
-        const char *x;
+        uid_t uid;
+        gid_t gid;
         int r;
 
+        if (argc > 1) {
+                log_error("This program does not take arguments.");
+                return EXIT_FAILURE;
+        }
+
         log_set_target(LOG_TARGET_AUTO);
+        log_set_facility(LOG_CRON);
         log_parse_environment();
         log_open();
 
+        umask(0022);
+
+        r = get_user_creds(&user, &uid, &gid, NULL, NULL);
+        if (r < 0) {
+                log_error("Cannot resolve user name %s: %s", user, strerror(-r));
+                return r;
+        }
+
+        r = load_clock_timestamp(uid, gid);
+        if (r < 0)
+                goto out;
+
+        r = drop_privileges(uid, gid, (1ULL << CAP_SYS_TIME));
+        if (r < 0)
+                goto out;
+
         assert_se(sigprocmask_many(SIG_BLOCK, SIGTERM, SIGINT, -1) == 0);
 
         r = manager_new(&m);
@@ -1064,20 +1218,24 @@ int main(int argc, char *argv[]) {
                 goto out;
         }
 
+        manager_add_server_string(m, NTP_SERVERS);
+        manager_parse_config_file(m);
+
+        r = manager_network_monitor_listen(m);
+        if (r < 0) {
+                log_error("Failed to listen to networkd events: %s", strerror(-r));
+                goto out;
+        }
+
+        log_debug("systemd-timesyncd running as pid %lu", (unsigned long) getpid());
         sd_notify(false, "READY=1");
 
-        FOREACH_STRING(x, "8.8.8.8", "172.31.0.1", "time1.google.com", "time2.google.com", "time3.google.com", "time4.google.com", "0.fedora.pool.ntp.org") {
-                r = manager_add_server(m, x);
-                if (r < 0) {
-                        log_error("Failed to add server %s: %s", x, strerror(-r));
+        if (network_is_online()) {
+                r = manager_connect(m);
+                if (r < 0)
                         goto out;
-                }
         }
 
-        r = manager_connect(m);
-        if (r < 0)
-                goto out;
-
         r = sd_event_loop(m->event);
         if (r < 0) {
                 log_error("Failed to run event loop: %s", strerror(-r));
@@ -1086,6 +1244,12 @@ int main(int argc, char *argv[]) {
 
         sd_event_get_exit_code(m->event, &r);
 
+        /* if we got an authoritative time, store it in the file system */
+        if (m->sync)
+                touch("/var/lib/systemd/clock");
+
 out:
+        sd_notify(false, "STATUS=Shutting down...");
+
         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 }